Field of the Invention
The present invention relates to a fuel cell stack.
Discussion of the Background
For example, a solid polymer-type fuel cell has an electrolyte film/electrode structure (MEA) in which an anode electrode is arranged on one surface of an electrolyte film including a polymer ion exchange membrane, and a cathode electrode is arranged on the other surface. A power generation cell (unit cell) is configured when the electrolyte film/electrode structure is put between separators. Normally, when a predetermined number of power generation cells are stacked, for example, the power generation cells are incorporated as an on-board fuel cell stack in a fuel cell vehicle (fuel cell electric vehicle, etc.).
In a fuel cell stack, a lot of power generation cells are stacked, and the power generation cells need to be accurately positioned with respect to each other in order to ensure desired sealing as the whole fuel cell stack.
In this regard, for example, there is a known method of assembling a fuel cell disclosed in Japanese Laid-open Patent Publication No. H9-134734. In this assembly method, a positioning hole for cell assembly is drilled in a pressure plate for pressing a stack, and a knock pin is inserted into the positioning hole for cell assembly in an erect posture. Subsequently, the knock pin is successively fit to cell positioning holes drilled in respective flat plate components, thereby configuring the cell.
Further, when the above-described operation is repeated, a predetermined number of power generation cells are stacked, and a stack is configured. Thereafter, when tightening and fixing are performed using a pressurization plate, the fuel cell is assembled.
For this reason, the flat plate components included in the fuel cell may be stacked without position shift to configure the power generation cells, and the power generation cells may be stacked without position shift and sealed at high accuracy.